Benzene does not undergo ?

Benzene (C₆H₆) is an aromatic hydrocarbon that exhibits remarkable chemical stability due to its delocalized π-electron system. The six carbon atoms in benzene form a planar hexagonal ring with alternating single and double bonds, but in reality, all C–C bonds are of equal length due to electron delocalization. This delocalized system is responsible for benzene’s aromaticity, which provides extra stability to the molecule.

Benzene readily undergoes electrophilic substitution reactions, such as nitration, sulphonation, halogenation, and Friedel-Crafts alkylation or acylation. In these reactions, one hydrogen atom of the benzene ring is replaced by another substituent while the aromatic π-system remains intact.

However, benzene does not undergo addition reactions like alkenes do. Addition reactions would require breaking the delocalized π-system, resulting in the loss of aromatic stabilization energy (around 150 kJ/mol). This would make the product far less stable than benzene itself. For example, if benzene were to undergo an addition of hydrogen or halogen, it would form a non-aromatic compound such as cyclohexane or hexachlorocyclohexane, which are thermodynamically less favored under normal conditions.

Even under harsh conditions, benzene resists typical addition reactions unless a strong catalyst or high temperature and pressure are applied. This behavior distinguishes aromatic compounds from alkenes and alkynes, which readily participate in addition reactions due to their localized double or triple bonds.

In short, benzene avoids addition reactions to preserve its aromatic character and stability. Therefore, while benzene easily undergoes substitution and oxidation reactions, it does not undergo addition reactions, as they would destroy its aromatic nature